A contour canal is an artificially-dug navigable
canal
Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface ...
which closely follows the
contour line
A contour line (also isoline, isopleth, isoquant or isarithm) of a Function of several real variables, function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a ...
of the land it traverses, in order to avoid costly engineering works such as:
* Digging a
cutting
Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force.
Implements commonly used for wikt:cut, cutting are the knife and saw, or in medicine and science the sca ...
or
tunnel
A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ve ...
through higher ground;
* Building an
embankment or
aqueduct over lower ground, or;
* Constructing a
canal lock
A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a chamber in a permanently fixed position i ...
(or series of locks) to change the level of the canal.
Because of this, these canals are characterised by their meandering course.
In the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
, many of the canals built in the period from 1770 to 1800 were contour canals - for example, the
Thames & Severn Canal completed in 1789, and the
Oxford Canal
The Oxford Canal is a narrowboat canal in southern central England linking the City of Oxford with the Coventry Canal at Hawkesbury (just north of Coventry and south of Bedworth) via Banbury and Rugby. Completed in 1790, it connects to th ...
completed in 1790. Later canals tended to be much straighter and more direct - a good example is the
Shropshire Union Canal
The Shropshire Union Canal, sometimes nicknamed the "Shroppie", is a navigable canal in England. It is the modern name for a part of the Shropshire Union Railways and Canal Company network. In the leisure age, two of the branches of that netwo ...
engineered by
Thomas Telford
Thomas Telford (9 August 1757 – 2 September 1834) was a Scottish civil engineer. After establishing himself as an engineer of road and canal projects in Shropshire, he designed numerous infrastructure projects in his native Scotland, as well ...
.
See also
*
Canals of the United Kingdom
The canals of the United Kingdom are a major part of the network of inland waterways in the United Kingdom. They have a History of the British canal system, varied history, from use for irrigation and transport, through becoming the focus of the ...
*
Grand Contour Canal - proposed, but never built
*
Lingqu Canal
The Lingqu () is a canal in Xing'an County, near Guilin, in the northwestern corner of Guangxi, China.
It connects the Xiang River (which flows north into the Yangtze) with the Li River (Guangxi), Li River (which flows south into the Gui ...
- the oldest contour canal in the world
Notes
References
*Day, Lance and Ian McNeil. (1996). ''Biographical Dictionary of the History of Technology''. New York: Routledge. {{ISBN, 0-415-06042-7.
Canals